1 Romeo (73.0 kg) entertains Juliet (54.0 kg) by playing his guitar from the rear of their boat at rest in still water, 2.50 m away from Juliet who is in the front of the boat. After the serenade, Juliet carefully moves to the rear of the boat (away from shore) to plant a kiss on Romeo's cheek. How far does the 76.0 kg boat move toward the shore it is facing?
在靜止的船尾若密歐(73.0kg)彈吉他取悅朱麗葉，朱麗葉離船頭有2.5m遠,小夜曲之後，朱麗葉小心地走到船尾（遠離海岸），給若密歐一個吻，那麼這隻76.0kg的船將向海岸移動多遠 ？
2 Batman, whose mass is 72.0 kg, is holding onto the free end of a 12.0 m rope, the other end of which is fixed to a tree limb above. He is able to get the rope in motion as only Batman knows how, eventually getting it to swing enough that he can reach a ledge when the rope makes a 58.0?angle with the vertical. How much work was done by the gravitational force on Batman in this maneuver?
一個美國留學生給的
2 Batman, whose mass is 72.0 kg, is holding onto the free end of a 12.0 m rope, the other end of which is fixed to a tree limb above. He is able to get the rope in motion as only Batman knows how, eventually getting it to swing enough that he can reach a ledge when the rope makes a 58.0?angle with the vertical. How much work was done by the gravitational force on Batman in this maneuver?
一個美國留學生給的